Vehicle stability control systems serve to intervene in critical situations such as, for example, understeering, oversteering or tilting. Intervention can be accomplished by means of, inter alia, braking interventions, in particular modulation of the brake pressure, so as to assist driving of the vehicle.
Input variables that are used in this context are measurement signals of different sensors, in particular of a yaw rate sensor, steering wheel angle sensor and lateral acceleration sensor as well as, if appropriate, of a longitudinal acceleration sensor. In addition, driving state variables such as, for example, vehicle mass and a reference speed, which are determined by other brake control systems such as ABS or EBS systems, are used to a certain extent.
In utility vehicles, stability control systems are used that have one control circuit for yaw control and a further control circuit for anti-tilt control. The anti-tilt controller generally receives input signals for the lateral acceleration, the vehicle mass and the vehicle reference speed and, if appropriate, a steering wheel angle signal. The yaw controller generally receives the steering wheel angle signal, the vehicle reference speed and the yaw rate signal.
The extensive sensor systems result in corresponding costs both for the hardware of the sensors used and for the software implementation. Furthermore, the sensors, in particular the yaw rate sensor, are susceptible to faults so that a high degree of expenditure on software development is necessary for reliable implementation.
Furthermore, the individual control channels give rise to corresponding costs for the brake system, the yaw controller in this context requiring two individual control channels for the front axle.